Floating dock structure



Nov. 18, 1969 J. w. BETHUREM 3,478,710

FLOATING DOCK STRUCTURE Filed July 31, 1968 2 Sheets-Sheet 1 r FF I L .dL. .J

38 FIG. INVENTOR.

J.W. BETHUREM Nov. 18, 1969 J. w. BETHUREM 3,478,710

FLOA T ING DOCK STRUCTURE Filed July 31, 1968 2 Sheets-Sheet FIG- 3 34INVENTOR. J. W. BETHUREM United States Patent Int. Cl. B63c 1/02 US. Cl.114-.5 Claims ABSTRACT OF THE DISCLOSURE A floating concrete dock isformed by connecting a number of identical, hollow, box-like concretestrlgptures in the desired pattern. The individual structures, areformed by providing a rigid welded steel frame having rectangular top,bottom and sides, securing panels to the frame interior to form a core,placing reinforcing g'Wll'fi around the core, and pouring high densityconcrete around the core, while utilizing the frame elements as theconcrete forms.

Background of the invention This invention relates to an improvedconcrete floating dock structure.

While concrete floating dock structures have not attained widespreaduse, they are known. Such docks offer obvious advantages, since they areimpervious to various corrosive factors, which affect wood or metaldocks. Also, concrete itself is a relatively inexpensive material andcan provide a strong and durable structure.

However, the weight of the concrete presents a serious drawback, and ifsufficient concrete were to be used to provide a strong and durablestructure, the dock would be extremely heavy and difficult to transportand move, and also it would draw too much water. While some attemptshave been made to overcome the problems associated with concrete docks,the solutions have resulted in docks which are difficult and expensiveto manufacture, excessively heavy, or of insufficient strength anddurability.

Summary of the invention According to the present invention, arelatively lightweight, very strong concrete floating dock structure isprovided which is relatively easy and inexpensive to manufacture and iseasily attachable to similar structures to form a flexible and durableboat dock.

More specifically, the dock structure is provided with a strong, rigidframe to which a relatively thin outer shell of reinforced concrete isattached to provide a relatively lightweight hollow structure.

Another feature of the invention resides in the fact that the frameforms a portion of the dock exterior and is used both as a portion ofthe forms for pouring the concrete and as a means for supporting theremainder of the forms during the pouring operation.

Still another feature of the invention resides in the provision of postsfor mooring boats to the dock or for connecting the dock units to oneanother, the post being rigidly attached to the frame.

Brief description of the drawings FIGURE 1 is schematic plan view of adock formed by connecting a number of the individual dock struc tures.

FIGURE 2 is a perspective view of the floating dock structure.

FIGURE 3 is a top plan view of the dock structure frame withintermediate portions of the frame removed and showing a corner of theframe in section with the side panels'of the core and side reinforcingmeans also shown in section.

3,478,710 Patented Nov. 18, 1969 FIGURE 4 is a partial side elevationview of one corner of the frame, with intermediate portions of the framemembers removed, as seen along the line 44 of FIGURE 3.

FIGURE 5 is a partial vertical section through the completed dockstructure as viewed along the line 5-5 of FIGURE 3.

Description of the preferred embodiment In the drawings, each individualfloating dock unit is indicated generally by the numeral 10. As 'bestseen in FIGURE 1, a number of the individual units can be connected toform a floating dock to which a boat 12 may be tied. As is apparent, theindividual units can be connected in a wide variety of relationships toform a dock of almost any configuration with almost any desired numberof individual slips of variable sizes.

Each box-like dock structure 10 has a rigid metal frame, indicatedgenerally by the numeral 14, including horizontal rectangular top andbottom portions 16 and 18 respectively, formed by conventional steelangle irons. The top portion 16 has opposite side members 20 and 22,which are preferably 8 feet in length, and opposite end members 24 and26, which are preferably 4 feet in length, and the members are welded toone another at their ends to form an approximate 4 foot by 8 footrectangle with the vertical leg of each member at the outside of theframe portion and the horizontal leg of each member extending from thelower end of the'vertical legs. The bottom frame portion 18 is identicalto the top portion 16 except that it faces downwardly so that thehorizontal legs of the angle iron members extend from the top of thevertical legs. The frame portions 16 and 18 also include threehorizontal braces 28 rigidly interconnecting the side frame members 20and 22 at approximately equal intervals.

Four upright corner members 30 rigidly connect the top and bottom frameportions at their four corners, the members 30 being formed by the samesize angle iron as the members 20, 22, 24 and 26 and being welded to theinterior edges of the horizontal legs of the frame members with theiropposite ends flush with said hori zontal legs. As best seen in FIGURE3, the corners of the upright members 30 face outwardly and fit into thecorners formed by the intersecting frame members 20, 22, 24 and 26.Upright braces 32 also rigidly interconnect the top and bottom frameportions adjacent to the connection of the horizontal braces 28 with theframe member 20 and 22.

A corner post 34 is welded to and extends upwardly from each of the fourcorners of the top frame portion 16. Each corner post 34 is formed by anupright, relatively short piece of angle iron, the corner of which fitsinto the corner formed by the intersecting vertical legs of the angleiron frame members 20, 22, 24 and 26 and the bottom of which rest on thetop of the horizontal legs of said members. Both legs of each cornerpost are provided with three triangularly arranged holes 36, whichaccommodate suitable fasteners for securing the individual dockstructures 10 to one another.

Similarly a bottom corner post 38 is attached to and projects downwardlyfrom each corner of the bottom frame portion 18, the bottom posts 38being identical to the posts 34 except that they are provided with asingle hole 40 in each leg.

A 4 foot by 8 foot panel 42 is disposed within the recess of the topframe portion 16 and is supported by the horizontal legs of the framemembers 20, 22, 24 and 26 and the horizontal braces 28. The panel 42 ispreferably formed by a standard 4 by 8 foot sheet of relativelyinexpensive building material such as inch plywood, fiberboard,plasterboard or the like, and is spaced a short distance from theupright legs of the frame members, the frame being slightly larger than4 by 8 feet. A bottom panel 44 is similarly disposed in the recess ofthe bottom frame portion 18, and four upright side panels 46 of the samematerial as the panels 42 and 44 extend between the top and bottom frameportions exteriorly adjacent to the corner members 30 and the verticalbraces 32, so that the top and bottom panels 42 and 44, and the sidepanels 46, in conjunction with the frame members form a closed, hollow,box-like structure or core. Preferably the upright members 30 are 1 /3foot long so that each side panel 46 is 1 /3 foot high, whereby the two4 foot by 1 /3 foot side panels and the two 8 foot by 1 /3 foot panelscan be made from a single standard 4 x 8 foot sheet of material.

Three layers of reinforcing wire mesh or screen 50 are disposed withinthe recess formed by the top frame portion 16 on top of panel 42, eachlayer of wire mesh substantially spanning the length and width of theframe. In the illustrated embodiment the middle layer of wire mesh iswelded to the top frame portion 16 to anchor the reinforcing wire mesh.Similarly, three layers of wire mesh 52 are disposed within the recessformed by the bottom frame portion 18, the middle layer again beinganchored to the frame. Also, three similar layers of reinforcing wiremesh 54 are wrapped around the four upright sides of the box-like coreexteriorly of the side panels 46 but interiorly of the exterior sides ofthe top and bottom frame portions, the middle layer of wire mesh 54again being welded to the top and bottom frame portions.

The recess formed by the top panel 42 and the top frame portion 16 isthen filled with a layer of high density concrete 56, the concrete 56being poured into the recess while the frame is resting on the fourbottom posts 38, and filling the interstices between the reinforcingscreens 50, which become imbedded in the contract. Thus, the panel 42and the top frame portion function as a form for the concrete 56, whichis finished off so that its top surface 58 is flush with the upper edgeof the top frame portion 16, which provides a striking surface for theconcrete. As is apparent, the top corner post 34 projects upwardly thruthe concrete, which seals against the corner posts and the vertical legsof the frame members. A sealing material can be provided on the framemember to assure adequate sealing.

After the concrete 56 is sufficiently set, the frame is turned over, andthe above procedure is repeated, filling the recess in the bottom frameportion 18 with a layer of concrete 60 having an outer surface 62 flushwith the ends of the vertical legs of the frame members.

After the concrete bottom is sufficiently set, an integral layer ofconcrete 64 is poured around the four upright sides exteriorly of theside panels 46 and between the top and bottom frame portions 16 and 18.The concrete sides 64 are imbedded in the reinforcing screens 54 andhave outer surfaces 66 flush with the exterior vertical legs of theframe members. The sides 64 are preferably poured in one operationwithout drying intervals for the individual sides to provide an integralconcrete structure. This is accomplished by securing fiat retainerpanels (not shown) against the exterior of the frame portion to hold theconcrete against the side panel 46 before the particular side is turnedfrom a horizontal position. The retainer panel is conveniently securedto the frame by means of bolts extending through the holes 36 and 40 inthe corner post members. After the retainer panel is bolted to theframe, the structure is rotated 90 and the procedure is repeated, untilall four upright sides are poured.

When the concrete sides 64 are sufficiently set, the side retainerpanels are removed and the concrete is cured. After the concrete iscured, the entire outer surface of the dock structure, which includesthe outer surface 58 of the concrete top layer 56, the outer surface 62of the bottom concrete layer 60, the outer surface 66 of the concretesides 64, and the exterior sides of the top and bottom frame portions,is coated with a layer 70 of moisture imprevious material. In thepreferred embodiment, an epoxy paint is applied to the exteiror andprovides a moisture resistant, tough, and durable finish. Preferably, atleast the upper surface 58 is provided with a textured finish tominimize individuals slipping on the dock structure when it is wet.

The individual dock units 10 can be fastened to one another by means ofconventional bolts extending through the holes 36 and 40 in adjacentunits to provide an overall dock of almost any desired configurationwith 4 and 8 foot increments in size. The upright corner posts 34 alsoprovide convenient means for securing boats to the dock or for theattachment of a canopy or other structure to the dock. Since theconnection between the individual units or between the dock and otherobjects is accomplished through the corner posts, which form an integralpart of the frame, the stresses on the dock unit are all taken by thestrong and rigid frame. Thus, since the concrete does not receivesubstantial stress, it need not be excessively thick, so that the dockunits are relatively light weight. As is apparent from the above,commercially available, relatively inexpensive materials are used toconstruct the dock units, so that the units are relatively inexpensivedespite their high strength, light weight, and durable construction.

I claim:

1. A floating dock structure comprising: a rigid metal frame includingsimilar, polygonal, generally horizontal and parallel top and bottomportions and a plurality of upright members rigidly connecting the topand bottom portions; panel means connected to the frame and forming asubstantially closed, hollow core in conjunction therewith and aconcrete, outer shell disposed around said core, and connected to theframe to form in conjunction with the frame a closed hollow structurehaving an outer surface with parallel horizontal top and bottom wallsand upright side walls connecting the top and bottom walls, saidstructure forming an interior closed chamber adapted to providesufficient buoyancy in water to float said structure with the top wallabove the water.

2. The invention defined in claim 1 and including a plurality of postmembers rigidly attached to the frame and projecting outwardly therefrombeyond the outer surface of the outer shell.

3. The invention defined in claim 1 and including reinforcing meansimbedded in the concrete outer shell and connected to the frame.

4. The invention defined in claim 1 wherein at least a portion of theframe is flush with the outer surface of the concrete shell, so that theframe and the concrete outer shell conjunctively form the outer surfaceof said closed hollow structure.

5. The invention defined in claim 4 wherein the upper frame portion isrectangular and includes four members joined at their ends, the membershaving L-shaped cross sections with upright and horizontal legs, theupright legs forming a portion of said outer surface side walls and thehorizontal legs being spaced interiorly from the outer surface of topwall.

6. The invention defined in claim 5 and including a plurality of uprightpost members rigidly attached to and extending upwardly from the upperportion frame members and projecting upwardly above the outer surface ofthe outer shell top wall.

7. The invention defined in claim 5 wherein the bottom frame portion hasthe same configuration as the top frame portion and includes four framemembers joined at the ends and having L-shaped cross sections withupright legs extending downwardly from the horizontal legs and forming aportion of the outer surface of the side walls, and the upright membersconnect the top and bottom frame portions at the four corners and arespaced inwardly from the outer surface of the outer shell.

8. The invention defined in claim 7 wherein the panel means includes topand bottom panels respectively supported on the horizontal portions ofthe top and bottom frame members and four upright side panels supportedon the upright frame members.

9. The invention defined in claim 8 and including at least one layer ofreinforcing wire outwardly adjacent to the top and bottom panelsrespectively and imbedded in the concrete outer shell and at least onelayer of reinforcing wire wrapped around the four upright side panelsexteriorily thereof and imbedded in the concrete outer shell.

References Cited UNITED STATES PATENTS 3/1962 Benson. 5/1963 Usab.

TRYGVE M. BLIX, Primary Examiner

